1. Field of the Invention
The present invention relates to an input device that inputs information according to an approach state of an object using a change in capacitance or the like, and a control method and a program therefor, and more particularly, to an input device that inputs information according to an operation of a finger, a pen, or the like in various information devices such as a computer.
2. Description of the Related Art
Since a sensor that detects a change in capacitance can detect approach of an object (for example, a finger or a pen) with a simple configuration, the sensor is widely used for user interface devices of various electronic devices, such as touch pads of note type computers or touch panels of smart phones.
In International Publication No. WO 2012/117437, a touch panel device including a touch panel unit in which a plurality of electrodes are arranged is described. A scan electrode is determined from among the plurality of electrodes of the touch panel unit, and the touch panel unit is operated for the determined scanning electrode. Accordingly, a measurement value reflecting a change in capacitance of each electrode is acquired, and it is detected whether the touch panel unit is touched based on the acquired measurement value.
However, since such an input device is configured to be able to sensitively detect an object approaching a detection surface of a sensor, there is a problem in that the sensor is particularly susceptible to electromagnetic noise from the outside. For example, in the case of the above-described capacitive sensor, since a change in capacitance of an electrode caused by approach of an object is detected as a change in a small amount of charge, there is a problem in that erroneous detection of coordinates or a contact state of an object easily occurs due to an influence of noise.